1. Field of Invention
The field of the currently claimed embodiments of this invention relates to methods of controlled delivery of substances within a body, and more particularly to methods of controlled delivery of substances within a body using submicron, heat-actuated containment vessels.
2. Discussion of Related Art
Mesoporous silica nanoparticles (MSNs) have attracted widespread research interest as functional materials.1-7 They are endocytosed by cells,1 are nontoxic,2 and can be used to deliver drugs.3 Recently, an amazing array of methods for controlling pores to trap and release cargo has been developed. These range from coatings on particles, to intricate nanovalves that control the pore openings using methods of light,4 pH,5 or redox6 for activation. For therapeutic applications, an external and noninvasive method of actuation is preferable for control of therapeutic effects. Light control has been demonstrated, but its practical applicability is limited due to shallow tissue penetration for photodynamic therapies. Nanovalves based on changes in pH are self-opening, but cannot be controlled by an external stimulus. Therefore, there remains a need for improved methods of controlled delivery of substances within a body.